Pulse counting tube



March 15, 1955 KAZAN 2,704,336

PULSE COUNTING TUBE Filed Jan. 3, 1951 2 Sheets-Sheet l mauuns 300wINVENTOR.

BENJAMIN KAZAN BY W Mn i J 3- N a 26x6 20555 i March 15, 1955 B. KAZANPULSE COUNTING TUBE 2 Sheets-Sheet 2 Filed Jan. 3, 1951 QUE LNHHHHOEICIONV INVENTOR.

BENJAMIN KAZAN BY gn M vdE United States Patent PULSE COUNTING TUBEBenjamin Kazan, Long Branch, N. 1., assignor to the United States ofAmerica as represented by the Secretary of the Army Application January3, 1951, Serial No. 204,257 14 Claims. (Cl. 31518) (Granted under Title35, U. S. Code (1952), sec. 266) The invention described herein may bemanufactured and used by or for the Government for governmentalpurposes, without the payment to me of any royalty thereon.

This invention relates to electron discharge apparatus and moreparticularly to electronic counters.

In the art of electronic counting, it is usually necessary to employ aseries of cascaded tubes together with appreciable associated circuitry.Such devices are of relatively large size and complex construction.Moreover, in view of the complex circuitry involved, such as electroniccounter may be relatively expensive to construct and difficult tomaintain in proper operating condition.

It is therefore an object of this invention to provide a simple andcompact means for registering the count of rapid impulses in a binary orhigher number system.

Another object is to make possible a self-resetting counter of compactand economical construction.

Still another object is to provide a simple and compact electronicdevice capable of yielding one output pulse in response to theaccumulation of a prescribed number of applied input pulses.

It is yet another object of my invention to enable selective deflectionof an electron beam in an electron discharge device in accordance withincoming signal pulses such that the beam will be held focused-upon adiscrete portion of the anode after cessation of each signal ulse. p Inaccordance with this invention, electron discharge apparatus especiallysuitable for counting comprises a strip cathode, an anode angularlydisposed with respect to the emitting surface of the cathode, means forproducing a constant magnetic field in the anode-cathode. region fordirecting the electron beam in a prescribed direction and deflecting thebeam in accordance with the polarity of the incoming pulse so. that itnnpmges upon successive portions of the anode.

In accordance with one illustrative embodiment of this I? invention, theelectronic counter comprises a strip cathode and an undulated arcuateanode mounted opposite said cathode, means for deflecting the electronbeam to successive positions on the anode in accordance with incomingsignal pulses, means for stabilizing the electron beam on a preselectedportion of the arcuate anode after each incoming pulse, and means forreturning the electron beam to its initial starting position after aprescribed number of successive lIlCOITllHg pulses.

. For a better understanding of the present invention to- H a getherwith other and further objects thereof, reference is had to thefollowing description taken in connection with the accompanying drawingsin which:

Fig. 1 is a perspective view of an electron discharge deviceillustrative of one embodiment of my invention;

Fig. 2 is a view in section along plane 2-2 of Fig. 1

and includes the electrical connections of electrodes shown in Fig. 1'

Fig. 3 is an explanatory diagrammatic curve;

Fig. 4 is a perspective view of an electrode assembly Like referencenumerals indicate similar parts through-" out the several views.

Referring now to Figs. 1-3, there is shown an electron discharge devicecomprising an evacuated envelope 2 hav- "ice ing mounted therein anelectrode assembly, which may be referred to generally by the referencecharacter 4.

The electrode elements are supported betwen a pair of spaced parallelinsulating members such as mica discs 6 and 8 and comprise respectivelycathode 10, anodes 12a to 12e angularly displaced with respect tocathode 10 and a collector anode 14. Encompassing the electrode elementis a cylindrical metal shield 16. The electrode assembly 4 may beconventionally supported from a stem 18 terminating in a press 20.Extending through the press 20 are conductors 22 for electricallyconnecting the electrode assembly 4 to the operating circuits.

Extending between the discs 6 and 8, and fitted in apertures therein, islinear cathode 10, which may be of the indirectly heated type,comprising a rectangular shaped sleeve 24 longitudinally positioned inapproximately a radial plane within envelope 2. A restricted portion ofone of the outer fiat surfaces of sleeve 24 is coated with a thinlongitudinal strip of thermionic material 26, such as barium orstrontium oxide. Heating current for the cathode is provided inaccordance with known practice. Surrounding cathode 10 is anaccelerating grid 28 which is maintained positive with respect to saidcathode by approximately 50 volts. By this arrangement, a ribbon shapedelectron beam of rectangular cross section is produced when theelectrodes are energized as hereinafter described.

A plurality of linearly aligned metal anodes 12a to 12e are angularlydisposed with respect to cathode strip 26. Considering the position ofcathode strip 26 on a reference longitudinal plane of zero degrees, theneach of the anodes 12 may be assumed to be in a longitudinal planeapproximately 230 clockwise from said reference plane. It will beunderstood, of course, that 230 is merely illustrative and that theanodes 12 may be longitudinally positioned at some other convenientangle with respect to cathode strip 26. The anodes may be equally spacedfrom one another by a distance approximately equal to their width, andare supported in position by means of apertures in the insulatingmembers 6 and 8. As shown, the anodes are connected together in a groupby a tie-wire 30, one end of which is connected to leadin conductor 32sealed in the press 20. Although five spaced anodes are shown in thespecific embodiment illustrated, a greater or lesser number of anodesmay be employed. The number of anodes used determines the number ofpulses the device may count. Thus, if five pulses are to be counted,five anodes are employed. If ten pulses are to be counted, then tenanodes are utilized. To collect the electrons which pass between theanodes 12, rectangular collector anode 14 is mounted in a lonfgitudinalplane behind anodes 12 and is spaced thererom.

As shown in Fig. 2, a load resistor 34 is connected between the anodes12 and collector anode 14 which is placed at a positive potential withrespect to the potential of cathode 10 by means of battery 36 or anyother suitable potential source. The incoming pulses are applied betweenterminals 38 and 40 and are coupled to the anodes 12 by capacitor 42.Also coupled to anode 12 is a utilization circuit 44 which may be of anyone of the conventional circuits well known in the art for dischargingthe anodes 12 when a predetermined potential is reached by said anodes.

A uniform axial magnetic field of prescribed intensity may be suppliedin any desired manner as by a coil 46 carrying a steady current inaccordance with known practice. As a result, the electron trajectory iscurved as shown in Fig. 2. The strength of the magnetic field and itsdirection are made such that, in the absence of incoming pulses, theelectrons emanating from the cathode 10 are concentrated into asubstantially curved rectangular beam 48 focused upon the anode 12a. Asis well known in the art, any change in potential applied to anode 12will interact with the prescribed axial magnetic field to change thecurvature of beam 48 and thus effectively shift the terminus of thebeam.

In operation, the anodes 12 are maintained at a moderately high positivepotential with respect to cathode 10, for example, several hundredvolts. As shown, this positive potential is applied to the anodes 12through load 'voltage. 'tially impinging upon any of the anodes 12, itis. autoresistor 34. If the positive pulses applied to the anodes 1 2through capacitor 42 are of 'sufiicient amplitude, then, as each of theanode voltage pulses are applied, interaction of the axialmagnetic fieldand the applied pulses :will cause curvature of beam 48 to change, and,consequently the terminus of the beam will be shifted from one anode tothe next adjacent anode. Thus if successive positive pulses of shortduration and suificient amplitude are coupled to the anodes 12throughcapacitor 42, the.b'eam terminus will be successivelyshifted'from the anode 12a to the anode 12e. To better explain theoperation, reference is made to the static characteristic curve shown.in

Fig. '3, illustrating the variation of anode currentwith respect toapplied anode voltage. The amount of current drawn by each of the anodeswill, of course, be dependent on the relative portion of beam 48 which'isintercepted by each anode as the beam is successively deflected fromanode 12a to 12e.- If, for example, beam 48 intercepts I a small portionof the surface of anode 12a, then little anode current will be drawn.However, if beam 48 covers all of anode 12a, then maximum anodecurrentwill be drawn. Thus, as the anode voltage is-increased, thecurrent at each of the anodes 12 will rise from zero'to a I 1:

anode circuit, a load line may be conventionally drawn in Fig. 3 asshown to determine the point-of operation, or

stability, for each successive anode. As is well .known in the art, onlythe points of intersection of theload line with the positive slopedportions of the undulated curve as indicated at U, V, W, X an Y will bestable, and are known as points of equilibrium. For example-if, for anyreason, beam-48 should be shifted by an increase in-anode voltage sothat more of the beam impinges on 12a-than that which corresponds to thevoltage U, then the current drawn through load resistor 34 willincrease, thereby causing a corresponding voltage drop acrossthe load sothat the anode voltage Will automatically be decreased and returntowardsthe voltage designatedat U: -'If, on

the other hand, beam 48 is shifted by a decrease in :anode voltage, theanode current drawn will correspondingly be decreased thereby causingthe anode voltage at 1211 to increase, thus tending to shift the beambackagain to the stabilized voltage point U. Thus if the beam positionis shifted by a change in the anode voltage, the

: change in intercepted beam current atthe anode will cause an oppositevoltage'chan'ge across'load resistor 34 which 'will tend to maintain thebeam in the equilibrium position. After a pulse is applied to the inputcircuit, beam 48 will be deflected from 12a to 12b, and only thatportion of thebeam will impinge on 12b so that the anode current drawnwill cause the anode potential to be -stabilized at a potentialrepresented by V'of Fig.3. This anode voltage, of course, is necessarilyhigher than. the plate voltage represented by U. That portion of beam 48not impinging on anodes 12- does not afiect the volt- 'agedrop acrossresistor 34 and-is intercepted-by collector anode 14. It can readily beseen therefore, that by impressing a succession-of voltage pulses on theanodes 12, the beam terminus may be successivelyshifted fromoneequilibrium, or stable, position to thenext. Thus, as

each successive pulse is applied to the anodes 12, the beam is shiftedor deflected to the next successive anode.

It will'be appreciated therefore that the beam may shift successivelyfrom one anode to the next by positive pulses supplied through capacitor42 and held upon any of the anodes 12 against which it is deflected byvirtue of the equlhbrium voltage points, each of which correspondsrepresented by the undulated curve illustrated in Fig. 3. 'With apredetermined load resistor such as 34 in the 4. -to anode 12a. ofcourse, if the polarity of the income ing pulse is reversed, the beamposition may be deflected in the opposite direction from anode 12s to12a, assuming the beam is positioned initially on anode 12e.

Fig. 4 illustrates anothervembodiment of an electrode assembly which maybemounted in evacuated tube 2 between spaced parallel insulating discs 6and 8.

Extending between discs 6 and 8 and centrally positioned withinevacuated tube 2 is a trough shaped cathode 50. To provide a rectangularshapedelectron beam, the outer surface of trough base 52 of "the cathodeis coated with a thin longitudinal stripv ofthermionic emitting material54,'such as barium or strontium oxide. Spaced from trough base 52 andparallel thereto, is an accelerating grid 56 which is provided with alongitudinal slot 58 disposed-opposite thermionic strip 54.

Encompassing cathode 50 and accelerating grid 56 is a coaxialcylindrical anode 60, which in turn' is surrounded by collectoranode 62radially spaced from anode 60. An integral portion of the cylindricalsurface of anode 60, for example, approximately 120, is provided with anundulated structure 64 which comprises a series of triangular shapedteeth 66a to 66k, hereinafter re+ ferred to as counting anodes, havingsuccessively increas ing peaks. As shown, the counting anodes 66 arearcu? ately disposed between exposed edges 68 and 70 of cylindricalanode 60. In the specific embodiment illustrated, thermionic strip 54 isaligned with :edge Y70 and, as hereinafter explained, the electron beamwill be deflected in a clockwise direction.

A load resistor 34 is connected between collector anode 62 and thecounting anodes 66. A suitable. sourceof 1 positive potential may beapplied to collector anode 62 by means of battery 36 or any othersuitable potential source. This positive potential is also applied tothe counting anodes 66 through load-resistor 34. A uniform axialmagnetic field of prescribed intensity may be supplied in any desiredmanner as by coil 46 carrying a steady current in accordance with knownpractice.- The constant magnetic field is made such that, in the absenceof incoming pulses, the electrons emanating from thermionic strip 54 andaccelerated by grid 56 are con: centrated .into asubstantially curvedrectangular beam thus impinging on anode 66a. The incoming pulses may becoupled to said countinganodes by means of capacitor 42 or by any othermeans well known in the art. Although in the specific embodimentillustrated, ten

counting anodes are shown, it is to be understood that 0 ':a lesserorgreater number of counting anodes may be employed, depending on thenumber of pulses: the de- 'vice may be required to count. Thus, inthcspecificillustration, ten pulses are to be counted. If five pulsesare tobe counted, then only five counting anodes are'utilized.

Spaced from counting anode 66k and parallel thereto, is a flybackcontrol plate 72. 'It is tobe assumed that the surface of the flybackplate is such that its secondary emission ratio is less than one whenbombardedas here- I inafter described. As shown in Fig. 5, flyback plate72 f and grid 56 are connected to common grid-leaklresistor to asuccessively higher value of D. C. equilibriumw',

Stated in another way, when the beam is .par-

matically held upon that anode until the next pulse is applied.

In the illustrative case shown in Fig. 1, it hasbeen assumed that, afterfive pulses, the anode-voltage corresponding to point Y of Fig. 3 issufiiciently high to trigger external utilization circuit 44. Thus,after :the fifth pulse, the counting sequence may be repeated. f

In the specific embodiment of the invention illustrated and 'abovedescribed, positive pulses have been applied to successlvely shift thebeam position from anode 12a 74, which in turn is connected to thepositive terminal of battery, 76 or other suitable source. Grid-leakcapacitor 78 is connected across resistor 74. This arrangement permitsthe counting tube to reset itself automatically after'th'e requirednumber of pulses have been applied tothe counting anodes 66 throughcapacitor 42.

7 During operation, thecounting anodesl66 are maintained at moderatelyhigh positive potential with respect tocathode 50. As successivenegativepulses of short duration are coupled to said counting'anodesthroughcapacitor 42, the electron beamwwillcbe shifted successively in aclockwise direction from counting anode 66a to counting anode 66k. As afunction of the anode voltage, the plate current may be represented bythe 'undulated curve shown in Fig. 6, the load line corresponding toresistor 34 beingindicated in the convntionaLmanner. As previouslyexplained, each incoming pulse shifts the beam to the.successivecounting anode where it automatically assumes .a state of stable voltageequilibrium indicated by points A to K in Fig.6. Consequently, when theelectron .beam is impinging upon a, particular anode, it isautomatically heldf upon that anode until the "next'pulse' 'is appliedatwhich time the beam is shifted to the adjacent anode. Thus, it will beappreciated that the beam is successively shifted clockwisealong thecounting anodes 66.

Upon application of the tenth input pulse, the electron beam impinges onflyback plate 72. As a result, control grid 56 is driven negative, thuscutting off the beam. When the negative charge has sufliciently leakedofi through grid leak resistor 74, the beam will return to anode 66a ata stable equilibrium voltage point. Thus after dthe tenth pulse thecounting sequence may be repeate It is to be understood, of course,that, if desired, the external utilization circuit described inconnection with Fig. 1 may also be used with the device shown in Fig. 4.By using this arrangement, flyback plate 72 may be eliminated.

While there has been described what is at present considered to be thepreferred embodiments of this invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention, and it is, therefore,aimed in the appended claims to cover all such changes and modificationsas fall within the true spirit and scope of the invention.

What is claimed is:

1. Electronic discharge apparatus comprising means for producing aribbon-shaped electron beam of substantially rectangular cross section,a target electrode intercepting the terminus of said beam, means forestablishing a constant magnetic field to deflect said ribbon-shapedbeam, said field being of such intensity as to focus the terminus ofsaid beam upon one end of said target electrode, means for successivelyshifting said beam to discrete portions of said anode for producing anundulated target electrode current with respect to electrode targetvoltage, and means for holding said beam on the discrete portions ofsaid anode against which it is directed.

2. Electron discharge apparatus comprising means for producing aribbon-shaped beam of substantially rectangular cross section, an anodeintercepting the terminus of said beam, means for establishing amagnetic field to concentrate said ribbon-shaped beam in a curved path,said field being of such intensity as to focus the terminus of said beamupon one end of said anode, a source of input pulses, means for applyingsaid input pulses to said anode whereby said beam is successivelyshifted to impinge on discrete portions of said anode to produce anundulated anode current with respect to anode voltage, and means forholding said beam on the discrete portions of said anode against whichit is directed.

3. Electron discharge apparatus comprising means for producing aribbon-shaped electron beam, a plurality of interconnected spaced targetelectrodes to intercept the terminus of said beam, means for producing aconstant magnetic field to concentrate said beam in a curved path, saidfield being of such intensity as to focus the terminus of said beam uponone of said target electrodes, means for shifting said beam successivelyfrom one target electrode to the next adjacent target electrode wherebyan undulated electrode current is produced, and means for holding saidbeam upon the electrode against which it is directed.

4. The electron discharge apparatus in accordance with claim 3 whereinsaid target electrodes are linearly aligned.

5. A pulse counting circuit comprising an electron tube, meanspositioned longitudinally within said tube to produce a ribbon-shapedbeam of substantially rectangular cross section, a plurality of spacedtarget anodes to intercept the terminus of said beam, said anodes beinglinearly aligned co-planar with said beam producing means and angularlydisposed therewith, means for producing a constant magnetic field toconcentrate said beam into a curved path and of such intensity as tofocus the terminus of said beam upon an end anode, means for shiftingthe terminus of said beam to successive anodes to produce an anodecurrent having an undulated characteristic with respect to anodevoltage, and means for holding said beam upon a portion of the anodeagainst which it is directed, said holding means comprising a loadimpedance having one end connected to said target anodes to provide aplurality of stable anode voltage points.

6. A pulse counting circuit comprising an electron tube, a cathodemounted longitudinally in a radial plane within said tube to produce aribbon-shaped electron beam, an accelerating grid encompassing saidcathode for the entire length thereof, a plurality of spaced targetanodes to intercept the terminus of said beam, said anodes beinglinearly aligned in a longitudinal plane angularly disposed with respectto said radial plane, means for establishing a uniform axial magneticfield to concentrate said beam in a curved path, said field being ofsuch intensity as to focus the terminus of said beam upon an end anode,means for shifting the terminus of said beam to successive anodes toproduce an anode current having an undulated characteristic with respectto anode voltage, and means for holding said beam upon a portion of theanode against which it is directed, said holding means comprising a loadresistor having one end connected to said target anodes to providesuccessive stable anode voltage points.

7. A pulse counter in accordance with claim 6 wherein said target anodesare angularly displaced approximately 230 with respect to said radialplane.

8. A pulse counting circuit comprising an electron tube, meanslongitudinally positioned in a radial plane within said tube forproducing an electron beam of substantially rectangular cross section, aplurality of spaced and linearly aligned target anodes to intercept theterminus of said beam, said anodes being positioned in a longitudinalplane angularly displaced with respect to said radial plane, means forestablishing a longitudinal magnetic field between said beam producingmeans and said anodes for deflecting said beam, said field being of suchintensity as to focus the terminus of said electron beam upon an endanode, means for applying input pulses to said anodes whereby said beamis shifted to impinge on successive anodes to produce successivediscrete anode voltages, and means for holding said beam upon the anodeagainst which is it directed, said holding means comprising a loadimpedance connected to said target anodes to provide a plurality ofstable anode voltage points.

9. A pulse counter in accordance with claim 8 wherein said anodes arespaced from each other a distance approximately equal to the width ofsaid anodes.

10. An electron discharge apparatus comprising means for producing aribbon-shaped electron beam of substantially rectangular cross section,an anode encompassing said electron producing means to intercept theterminus of said beam, an integral portion of said anode having anundulated surface opposite said cathode, means for establishing aconstant magnetic field to concentrate said electron beam in a curvedpath, said field being of such intensity as to focus the terminus ofsaid curved beam upon one end of said undulated surface, means forsuccessively shifting said electron beam to discrete portions of saidundulated anode surface, and means for holding said beam in the discreteportion of said undulated anode against which it is directed.

11. An electron discharge apparatus in accordance with claim 10 whereinsaid undulated surface comprises a plurality of triangular shaped teeth.

12. An electron discharge apparatus in accordance with claim 10 whereinsaid holding means comprises a load impedance connected to said anode.

13. A pulse counting circuit comprising an electron tube, means axiallypositioned within said tube for producing a ribbon-shaped electron beam,an anode encompassing said electron source to intercept the terminus ofsaid beam, an integral portion of said anode having an undulatedsurface, said undulated portion comprising a plurality of triangularshaped target anodes having successively increasing peaks, the first ofsaid target anodes being substantially aligned with said beam producingmeans, means for establishing an axial magnetic field to concentratesaid electron beam in a curved path, said field being of such intensityas to direct the terminus of said curved beam upon a portion of saidfirst target anode, means for applying input pulses to shift theterminus of said beam to successive target anodes, means forsuccessively holding said beam on a portion of the anode target againstwhich it is directed, said holding means comprising a load impedancehaving one end connected to said anode, and means for deflecting saidbeam to again impinge the terminus of said beam on said first anodetarget after the application of a predetermined number of said inputpulses.

14. The pulse counting circuit in accordance with claim 13 wherein saidlast mentioned means comprises a 2,027,017 Brett Jan. 7, 1936 -2,07 5478Linder Mar. 23, 1937 "2,224,677 Hanscom Dec. 10, 1940 Fleming-Willi 1y10,-1945 Skelle'tt Feb 19,1946 Montani Mar} 8, 1 49 Clark June 28, 1949Skellett July 5, 1-949 Alfven at al June 27; 1950 Clark =Ot. 9, 1951

